/*
 * JHeuristics - The Java Meta-Heuritics Library
 * Copyright (C) 2004-2005, Universidade Federal de Campina Grande. All rights reserved.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package org.jheuristics.ga.operators;

import org.jheuristics.ga.DefaultPopulation;
import org.jheuristics.ga.GAConfig;
import org.jheuristics.ga.GAStatus;
import org.jheuristics.ga.Population;

/**
 * TODO
 *
 * @author Marcell Manfrin, marcell@ourgrid.org, Jan 9, 2006
 */
public class StatusPopulationChooser {
	public static final PopulationChooser CURRENT = new ChooseCurrent();
	public static final PopulationChooser AVALIABLE = new ChooseAvaliable();
	public static final PopulationChooser SELECTED = new ChooseSelected();
	public static final PopulationChooser TEMP = new ChooseTemporary();

	public static final PopulationChooser FAKE = new FakeChoose();

	
	/**
	 * TODO
	 */
	private StatusPopulationChooser() {
	}

	/**
	 * TODO
	 *
	 * @author Marcell Manfrin, marcell@ourgrid.org, Jan 9, 2006
	 */
	private static class ChooseCurrent implements PopulationChooser {

		/**
		 * TODO
		 *
		 * @param status
		 * @param config
		 * @return
		 * @see org.jheuristics.ga.operators.PopulationChooser#choose(org.jheuristics.ga.GAStatus, org.jheuristics.ga.GAConfig)
		 */
		public Population choose(GAStatus status, GAConfig config) {
			if (null == status) {
				// TODO: ERROR MSG
				throw new NullPointerException();
			}
			return status.getCurrentPopulation();
		}

	}

	/**
	 * TODO
	 *
	 * @author Marcell Manfrin, marcell@ourgrid.org, Jan 9, 2006
	 */
	private static class ChooseAvaliable implements PopulationChooser {

		/**
		 * TODO
		 *
		 * @param status
		 * @param config
		 * @return
		 * @see org.jheuristics.ga.operators.PopulationChooser#choose(org.jheuristics.ga.GAStatus, org.jheuristics.ga.GAConfig)
		 */
		public Population choose(GAStatus status, GAConfig config) {
			if (null == status) {
				// TODO: ERROR MSG
				throw new NullPointerException();
			}
			return status.getAvaliableIndividualsPopulation();
		}

	}

	/**
	 * TODO
	 *
	 * @author Marcell Manfrin, marcell@ourgrid.org, Jan 9, 2006
	 */
	private static class ChooseSelected implements PopulationChooser {

		/**
		 * TODO
		 *
		 * @param status
		 * @param config
		 * @return
		 * @see org.jheuristics.ga.operators.PopulationChooser#choose(org.jheuristics.ga.GAStatus, org.jheuristics.ga.GAConfig)
		 */
		public Population choose(GAStatus status, GAConfig config) {
			if (null == status) {
				// TODO: ERROR MSG
				throw new NullPointerException();
			}
			return status.getSelectedIndividualsPopulation();
		}

	}

	/**
	 * TODO
	 *
	 * @author Marcell Manfrin, marcell@ourgrid.org, Jan 9, 2006
	 */
	private static class ChooseTemporary implements PopulationChooser {

		/**
		 * TODO
		 *
		 * @param status
		 * @param config
		 * @return
		 * @see org.jheuristics.ga.operators.PopulationChooser#choose(org.jheuristics.ga.GAStatus, org.jheuristics.ga.GAConfig)
		 */
		public Population choose(GAStatus status, GAConfig config) {
			if (null == status) {
				// TODO: ERROR MSG
				throw new NullPointerException();
			}
			return status.getTempIndividualsPopulation();
		}

	}
	
	private static class FakeChoose implements PopulationChooser {

		/**
		 * TODO
		 *
		 * @param status
		 * @param config
		 * @return
		 * @see org.jheuristics.ga.operators.PopulationChooser#choose(org.jheuristics.ga.GAStatus, org.jheuristics.ga.GAConfig)
		 */
		public Population choose(GAStatus status, GAConfig config) {
			return new DefaultPopulation();
		}

	}

}
